"From the earliest medical texts that we have, in the so-called Hippocratic Corpus which is 3,000 years old, mental illness is treated by physicians. However, physicians and priests are very, very closely aligned, and mental illness is understood oftentimes in terms of violations of taboos, things that might have a, can we say, moral overlay.

"Modern medicine, starting really in the 17th and 18th century, starts to think about mental illness as a disease of (to use an 18th-century word) the faculties, of mind rather than morals. And so what happens in the Enlightenment, first of all in Britain then in France, right around the time of the French revolution, then in Germany by the 1830s, is the notion that the therapies for mental illness are therapies to correct antisocial behaviors, but it means that it can be corrected.

"So the asylum, we always think about Bedlam Asylum in London, goes from some place where people are restrained, literally restrained with shackles, to places by the 1830s and 1840s where the asylum is seen as a big family, people in asylums grow their own food, there are dances on the weekends. The head of the asylum is seen as almost the father of the asylum and that term is used over and over again. And so that's a big shift from the idea of un-treatability to the idea of treatability, from moral failing to behavioral change."